Circumambulation ---> 1+(-)1=North

[David Merrill]

If F=mA and light "slows down" as it goes thru a medium, then what is the Force which accelerates said light? Does not that light require a mass?

If light "slows down" then what is the nature of the drag [friction] which decelerates said light? That would require light to have mass. And if light has mass, then there must be a force to decelerate and accelerate light. That is if you accept that light has mass.

The acceleration has a factor of time, from the velocity d/t.

Your question has me pondering how it might be explained. You are talking about light as it passes through a lens? The question is what causes the light to accelerate back to c when it gets out of the lens (glass medium). So light will "travel" at c when it is in a vacuum. Return it to the vacuum and it resumes its optimal speed at c.

I may have been dodging answering that question all this time by solving it around time being an illusion of ego.

P.S. I am starting to get it, I think. The presumption that light has mass is accompanied by another presumption; that it started on one side of the glass, and was going from there to the other side and on through, and then kept going on its way.

Suppose like the duatomic gold that once separated the two particles have affinity to each other, that they duplicate changes in characteristics that that the entire universe does this naturally except where affected by mind.